Regulator control system



y ,1 F. J. CHAMFLHN REGULATOR CONTROL SYSTEM Filed June 23, 1934 Fig.1.

TORQUE NEUTRAL MAX. LOWER.

MAX BOOST Inventor: Frankl in JCham plin, 490ml His ttorne g.

Patented July 16, 1935 H 2,008,542

UNITED STATES PATENT OFFICE 2,008,542 REGULATOR CONTROL SYSTEM FranklinJ. Champlin, Dalton, 'Mass., assignor to General Electric Company, acorporation of New York Application June 23, 1934. Serial No. 132,053

4 Claims. (01. 171 119) My invention relates to regulator controlsyspractically impossible to stop a regulator exactly tems and moreparticularly to an improved autoat either of its maximum positions.Mechanmatic control system for induction voltage regical torque isproduced in an induction regulator ulators. in a manner similar to theway torque is devel 5 An induction voltage regulator is essentially opedin an induction motor and when short cirl a transformer whose voltageratio is made varicuit currents are passed through the regulator able byrelatively rotating its primary and secthis torque sometimes attainsvery high values ondary windings. When the windings are in and notinfrequently results in injury to the rega given relative position amaximum voltage in ulator and its operating mechanism. Still a onedirection is induced in the secondary winding, further advantageousresult is that when the reg- 1. while if the movable winding is rotated180 eleculator is at or near its neutral position, its through tricaldegrees a maximum voltage in the other impedance is higher than when itis at or near direction is induced in the secondary winding. either ofits extreme positions, so that when the These two positions of theregulator are referred regulator is at or near its neutral position itis to as the positions of maximum boost and maximore effective inlimiting short circuit currents 1i mum lower because when the regulatoris conthan when it is at or near its extreme position. nected in acircuit, the regulator voltage either I am aware that devices known tothe art as adds to or subtracts from the circuit voltage in low voltagecutouts have been employed in conthese two positions. When the normallymovable nection with the control of induction voltage winding is rotatedonly 90 electrical degrees the regulators. These cutouts are simplyundervolt- 2e regulator is in its so-called neutral position and agerelays which heretofore have served to reno voltage is induced in thesecondary winding. verse the connections between the contact Inductionvoltage regulators are usually conmaking voltmeter and the operatingmotor when nected to the circuit to be regulated in such a the voltageof the regulated circuit is below a 2:, manner that the secondarywinding is in series predetermined value, with the result that the inthe circuit to be regulated and the primary regulator is then runapproximately to its maxiwinding is connected in shunt with the circuitmum voltage lowering position, whereas without o be ulated. Theregulator is usually oper the low voltage cutout the ordinary action ofated by a reversible operating motor whose di the contact makingvoltmeter would be such as rection of rotation is controlled by avoltage to run the regulator to its maximum voltage 30 responsivecircuit controller of the type known boosting position in its attempt tomaintain the to the art as a. contact making voltmeter. circuit voltageat itsnormal value. The theory In accordance with my invention, Iprovide on behind this has been that if the regulator is altomatic meansresponsive to a p edete ed 8blowed to be run to its maximum voltageboosting as normal condition of the regulated circuit for position onundervoltage t ubsequent aut y placing the regulator as near to torationof voltage will result in a momentary its n ut a p n as is p a newn ofexcessively high voltage on the regulated circuit, wh other position itmay be in at e me the and this high voltage may injure certain loadabnormal COIlditlOn OCClll'S. The predetermined devices, such forexample, as incandescent 4o abnormal condition may be loss of voltage onthe lamps. Consequently, it was thought that maxiregulated circuit, suchas is caused by a short mum safety would be Secured by running tregcircuit thereon. Such control of the regu a later to its maximumlowering position on underpmduces {number of deslrabl? t one voltage.However, due to "difierences in limit Such result is that whertvoltageagam res tored switches, regulator speeds, inertias, etc., it is, as

P regmaited clrcult the regulator be a practical matter, impossible tostop a regulator m Its therorencal m or posmol} so exactly on itsmaximum lowering position and in that on the average it should requirebut little m t 1 tors ha 6 been d d t motion from this position in orderto restore 6 ms rfagu a V roye ue o the circuit voltage in its regulatednormal value the excessively high torques developed therein,

Another advantageous result is that when the by F clrcult curr ents wthey near 50 regulator is near its neutral position, the their maximumlower ng posit ons. In my invenchamcal torque which is produced in thereal. tion, however, this difficulty is overcome and at lator is lessthan when the regulator is in any the same tim he reg l tor i preventedfrom other position except those of exact maximum going to its maximumboosting position so that boost or lower and, aswill be explained later,it is these is no danger of having momentary exces- 56 the followingdescription taken in connection with the accompanying drawing and itsscope will be pointed out in the appended claims. In the drawing, Fig. 1is a diagrammatic view of an embodiment of my invention and Fig. 2 is aregulator torque-position. curve for showing that maximum torques aredeveloped just off the maximum positions.

" Referring now to Fig. 1 of the accompanying drawing wherein I haveshown my invention asapplied to an electrical distribution systemcomprising an alternating current supply circuit I which energizes afeeder circuit 2 for a load circuit 3. Connected in the feeder circuitZislan induction voltage regulator 4 which is arranged to be controlledby a contact making voltmeter 5 having an operating winding 6 connectedto respond to 'the'volt'age of circuit 3. Regulator; 4

isarranged to be operated by a reversible oper'-" ating motor I which isprovided with reversing field windings 8 and 9, respectively; Contactmakingvoltmeter 5 is provided with a setof socalled raise contacts landa set of so-called lower contacts II for controlling the energization ofmotor 7 through the reversing field windings'B and 8, respectively. Anysuitable source of current supply may be provided for energizing themotor 'i andas shown, there is illustrated a battery i2 for thispurpose. The operating'circuit, whereby contacts control the motor I V 7through the winding 9 is completed through ;a

set of contacts [3 on a devicewhich may be referred to as a low voltagecutout, and as shown this device is provided with an operating windingit connected to respond to the voltage of circuit 3. This device is soarranged that when the voltage of circuit 3 is above a predetermined lowvalue the contacts l3 are. closed. Whereas if the voltage of circuit 3falls below this predetermined low value, contacts l3 open and a secondset of contacts IE on the device close.

For insuring that the regulator is run approximately to its neutralposition upon the occurrence of predetermined low Voltage conditions oncircuit 3, I provide a neutral position switch I6, which is mechanicallyoperated by the regulator'fi and which has a movablejcontact I! forcooperation with stationary segmental contacts l8 and i9, respectively-The arrangement is such that when the regulator'is. in its'neutralposition the'contact ii is midway between the contacts Band l9 and isout of engagement with either of these contacts, whereas when theregulator is in any other position contact I! is'in engagement with oneor the other of the contacts 18 .or.

8 and S of the motor l.

The operation of the illustrated embodiment of my invention is asfollows: With the parts in the positions shown in the drawing thevoltage on circuit3 is normal, for neither of the contacts. In or i l ofthecontact making voltmeter are closed. If the voltage should riseabovenormal the energization of winding 6 would increase sufficiently toclose the contacts I l, whereby a circuit is completed for the motor ithrough the battery I 2 and field winding 8, thereby causing the motor 7to operate in such a direction as to lower the voltage V of circuit 3.If now the voltage of circuit 3 should fall slightly below normal thecontacts iii of the meter would close thereby completing a circuit fromthe battery l2 through the contacts Iii, the contacts E3 of the lowvoltage cutout and the field winding 9 of the motor l whereby the motoris reversed and the regulator is rotated in such a direction as to raisethe voltage.

Assume now thata' short circuit occurs on circuit 3 or circuit 2, orthat for any other reason the voltage of circuit 3 falls below thepredetermined value atwhich the low voltage cutout operates. Under theseconditions the contacts ID of the contact making voltmeter 5 close butalso the contacts is of the low voltage cutout open and the contacts 15thereofclose. Due tothe fact that the contacts 7 l3 open the circuit forenergizing the motor 7 through the field winding 9 is broken so thatthis motor cannot operate in a-direction to cause the regulator to bemoved to its maximum boost or raising position. However, theclosure ofthe contacts iii completes a circuit from the -battery l2, through thecontacts l0 and the contacts I 5 in series} to the movable contact ll ofthe neutral position switchand from there the circuit is completedthrough the segmental contact 19 and the field winding 8 and through themotor back to the battery. Neutral position switch i6 is so arrangedthat when the contact ll engages the contact Hi the regulator is in aposition on the boosting side of its neutral position. Consequently,when the circuit through d will be substantially in -its neutralposition.

Should the regulator have been on the lowering side or its neutralposition the contact ll would have been in engagement with the contactl8 and as the contact I8 is connected to the field winding 9 the motorwould have been operated in the opposite direction, that is, in araising direction until it reached its neutral position. g r

' Upon restoration of the circuit voltage, the low voltage cutout againopens its contacts l5 and closed contacts l3 whereby the motor 1 isagain completely under the control of contact making voltmeter 5 and theregulating system operates in the conventional manner to holdsubstantially constant voltage. I From Fig. 2, which is illustrative ofrelative torque values rather than actual torque values, it will be seenthat the torque-position curve of a regulator is steepest just 01f itsmaximum positions, and that it is relatively low and fiat near theneutralposition. This explains why slight inaccurraci es in stopping theregulator at its maXimum lowering position result in much higher torquethan similarinaccuracies in stoppingthe regulator at its neutralposition 'While I have shown and described a particular embodiment of myinvention, itiwillbe obvious to those skilled in the art that variouschanges and modifications may be madetherein without departing from myinvention, and I, therefore, aim in the appended claims to cover allsuch changes and modifications as fall within the true spirit and scopeof my invention;

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. In combination, an electric circuit, an induction voltage regulatorconnected thereto, said regulator having a neutral position, means forcontrolling said regulator in response to the voltage of said circuit,and means responsive to a predetermined abnormal condition of saidcircuit for putting said regulator substantially in its neutral positionregardless of what other position it may be in when said abnormalcondition occurs.

2. In combination, a voltage regulating system including an inductionvoltage regulator having a neutral position, and means responsive topredetermined low voltage condition of said system for automaticallyplacing said regulator substantially in its neutral position regardlessof what other position it may be in when said low voltage conditionoccurs.

3. In combination, an alternating current circuit, an induction voltageregulator connected thereto, a neutral position switch for saidregulator, a contact making voltmeter for controlling said regulator,and a low voltage cutout connected to control said regulator throughsaid neutral position switch.

4. In combination, an electric circuit, means including a rotatablemember arranged to be operated in either direction from a neutralposition between predetermined operating limits for controlling anelectrical characteristic of said circuit, operating means responsive tosaid electrical characteristic for normally controlling the operation ofsaid rotatable member between its operating limits, and means responsiveto a value of said electrical characteristic below a predetermined valueand operative jointly with said operating means for operating saidrotatable member to its neutral position.

FRANKLIN J. CHAMPLIN.

